CN104525861A - Engine cam and production method thereof - Google Patents

Engine cam and production method thereof Download PDF

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Publication number
CN104525861A
CN104525861A CN201410659401.8A CN201410659401A CN104525861A CN 104525861 A CN104525861 A CN 104525861A CN 201410659401 A CN201410659401 A CN 201410659401A CN 104525861 A CN104525861 A CN 104525861A
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China
Prior art keywords
cam
tic
titanium plate
matrix
engine
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CN201410659401.8A
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CN104525861B (en
Inventor
许云华
赵娜娜
梁淑华
钟黎声
燕映霖
叶芳霞
王娟
邹军涛
肖鹏
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Xian University of Technology
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Xian University of Technology
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/02—Sand moulds or like moulds for shaped castings
    • B22C9/04—Use of lost patterns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D18/00—Pressure casting; Vacuum casting
    • B22D18/06—Vacuum casting, i.e. making use of vacuum to fill the mould
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D19/00—Casting in, on, or around objects which form part of the product
    • B22D19/08—Casting in, on, or around objects which form part of the product for building-up linings or coverings, e.g. of anti-frictional metal
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/02—Valve drive
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)

Abstract

The invention provides an engine cam and a production method thereof. The surface of the work position of the engine cam is provided with a carbide coating, The work position of the surface of the cam is provided with the carbide coating. A quasi monocrystalline TiC dense ceramic layer, a micrometer TiC ceramic layer and a TiC-matrix fusion layer are sequentially distributed in a gradient manner from outside to inside, and are applied to the surface of carbon steel. The carbide coating can be applied to the surface of the carbon steel. The carbide coating is formed on the surface of a matrix through the cast matrix and titanium complex, the introduction of an external carbon source, heating and heat insulation, the coating and the substrate are metallurgically bonded, and the bonding force is very strong, so the problems of non-metallurgic bonding between present hard particles and the steel substrate, very weak bonding force and easy shedding of the particles are overcome, and the wear resistance of the work surface of the cam is greatly improved.

Description

Engine cam and preparation method thereof
Technical field
The present invention relates to one and there is wear-resistant coating hybrid engine cam and preparation method thereof, particularly relate to a kind of hybrid engine cam with wear resistant carbide coating and preparation method thereof, be specifically related to a kind of wear resistant carbide coating hybrid engine cam being applied to steel surface and preparation method thereof.
Background technology
Cam is one of key components and parts of automobile engine, not only subjects certain load, and undergos long wearing and tearing, and its performance quality directly affects quality and the life-span of automobile.Cam is a part important on camshaft, camshaft is primarily of a few part composition such as cam, bearing journal, axle journal, in order to control valve by certain order of work and the timely opening and closing of port timing, and ensure that valve has enough lifts, to the performance of whole air distribution system, there is decisive role.During its work, very high periodic contact stress and relative sliding velocity is faster had between cam face and tappet, and in Machine Movement Process, produce high temperature, cause cam often occur scratch, spot corrosion, wearing and tearing, edge be full of cracks with cam face and the form inefficacy such as to peel off, therefore require that cam material has good rigidity and fatigue resistance and good anti-wear performance.
At present, the material producing cam both at home and abroad mainly contains forged steel and two kinds, cast iron.In the past, motorcar engine many employings forged steel cam.In recent years, in order to reduce production cost, improve processing characteristics, the production of motorcar engine cam starts to adopt various cast iron materials.Meanwhile, from the condition of work of cam, its key wear is fricative by between cam face and tappet, requires very high to the hardness of cam portion and anti-wear performance.Therefore, in the outer car cam of Present Domestic is produced, cast iron has become the material of extensive use.Casting technique and the surface peening of next cam are also the problems must investigated in preparation process.During cam work, not only stand long wearing and tearing, cam is as axial workpiece simultaneously, and subject certain load, its surface is often in maximum stress state, and media environment is complicated.Therefore, the inefficacy of part and destruction also mostly occur in surface or from surface, as introduced certain residual compressive stress on part top layer, increasing case hardness, improving textura epidermoidea etc., just can improve fatigue strength and the wearability of part significantly.Surface intensified technique can be moulded in guarantee part entirety, effectively improve surface layer abrasion-proof and fatigue resistance while toughness, sometimes can also improve decay resistance, manufacture field at cam, bent axle, travelling gear etc. and obtain extensive use.At present, in cam is produced, the surface intensified technique often used mainly contains quenching technical and remelting processing, in addition, also has bath nitriding technique etc.
The coating of carbide material uses more a kind of material at present stage, and hardness is high, abrasion resistance properties is superior feature that it has, covers with coating way wearability and the life-span that the parts prepared by matrix material can be improved in metal carbon base body surface.Wherein TiC is a kind of common coating material, and it has following advantageous features:
(1) combination property of the excellences such as density is low, intensity is high, elastic modelling quantity is high, wear-resisting, corrosion-resistant, anti-oxidant is possessed;
(2) its particle is generally in spherical shape, and its lattice structure is face-centred cubic structure, has very high heat endurance and hardness;
(3) be convenient to machining, welding, forging, and process thermal deformation is little, and there is the cold and hot working performance of common steel-smelting.
Therefore, TiC coating is widely used as chipless cold/hot metal machining tool, cutting tool, various mould, the anti-corrosion piece surface of antiwear heat resisting etc.
Metal current material surface coating technology has: laser cladding, self-propagating high-temperature sintering technology, PM technique, material vapor deposition technique (comprising: chemical vapour deposition (CVD) (CVD), physical vapour deposition (PVD) (PVD)) etc., but, there is the deficiencies such as production equipment requirement is harsh, production efficiency is low, anchoring strength of coating is low in these methods.Therefore the coating of TiC phase how is obtained at engine cam working surface, and select the preparation method that a kind of production equipment is simple, technological process is short, to obtain with good, the difficult drop-off of basal body binding force and the coating of mechanical property, anti-wear performance excellence is problem demanding prompt solution.
Summary of the invention
The defect existed for above-mentioned prior art and deficiency, the object of the present invention is to provide a kind of engine cam, the surface of its working position has a kind of wear-resistant coating, this wear-resistant coating is TiC dense ceramic layers, this coating is favourable ensures that cam face has very high hardness and good wearability and fracture toughness, and cam intrinsic silicon has good toughness.Have and a kind of preparation method for obtaining above-mentioned engine cam is provided.
Further, the present invention also provides a kind of engine cam, the surface of its working position has a kind of gradient composite coating, it is preferably coated on the matrix surface of engine cam working position, to improve wearability and the fracture toughness on its surface, and provide a kind of preparation method for obtaining above-mentioned coating.
Described engine cam, has wear-resistant coating in its working position, and this coating favourable guarantee engine cam surface has very high hardness and good wearability, and cam itself has good toughness.
For realizing the object of the invention, present invention employs following technical scheme:
A kind of engine cam, have wear-resistant coating at its working face, it is characterized in that, this wear-resistant coating is TiC dense ceramic layers.Preferably, TiC dense ceramic layers is as the criterion monocrystalline phase, and described accurate monocrystalline refers to mutually, between polycrystalline phase and monocrystalline mutually between, compared to polycrystalline phase, uniform orientation is high, crystal boundary obviously reduces, and the microscopic structure that atomic arrangement is more orderly.
Preferred, along TiC dense ceramic layers along coating longitudinal profile, its thickness is 70-200 μm, is preferably 100-200 μm, is more preferably 120-200 μm; Preferably, the volume fraction of TiC is greater than 80%, is preferably greater than 90%; TiC dense ceramic layers particle diameter is 8-50 μm, is preferably 10-50 μm.
In addition, the present invention also provides a kind of engine cam, has gradient composite coating at its working face, and described gradient composite coating is carbide coating, comprises the fused layer of the TiC dense ceramic layers of distribution gradient successively, micron TiC ceramic layer, TiC and steel matrix.
Preferably, TiC dense ceramic layers is as the criterion monocrystalline phase.Described accurate monocrystalline refers to mutually, and uniform orientation is high, crystal boundary obviously reduces, and the microscopic structure that atomic arrangement is more orderly.Accurate monocrystalline is between polycrystalline phase with monocrystalline phase, and compared to polycrystalline phase, the crystal boundary of accurate monocrystalline phase obviously reduces, and dislocation density is low, has more sub boundary, and therefore hardness has obvious lifting; And than monocrystalline phase, it requires lower to preparation method, and organize more stable.
More preferably, along TiC dense ceramic layers longitudinal profile, its thickness is 70-200 μm, is preferably 100-200 μm, is more preferably 120-200 μm; Preferably, wherein the volume fraction of TiC is greater than 80%, is preferably greater than 90%; Particle diameter is 8-50 μm, is preferably 10-50 μm.
Preferred further, along micron TiC ceramic layer longitudinal profile, its thickness is 50-150 μm, is preferably 70-150 μm, is more preferably 80-150 μm; Wherein the volume fraction of TiC is greater than 80%, is preferably greater than 90%, and its particle diameter is 5-15 μm, is preferably 6-12 μm, is preferably 8-10 μm.
Further, along the fused layer longitudinal profile of TiC and matrix, its thickness is 50-200 μm, is preferably 100-200 μm; Wherein the volume fraction of TiC is 20-80%, and be preferably 50-85%, its particle diameter is 1-10 μm, is preferably 2-8 μm.
Preferably, gradient composite coating gross thickness is 170-550 μm; Be preferably 300-550 μm.
More preferably, described engine cam take carbon steel as matrix, and selected plain steel is mild steel, medium carbon steel and high-carbon steel, is preferably: Q275A, Q255AF, 45 steel, T12A, T8, ZG270-450 etc., sees standard GB/T 221-79.Matrix according to heat treatment mode be not all in pearlite, martensite, ferrite, bainite, austenite and sorbite one or more.
The invention provides a kind of preparation method of engine cam, its working surface has wear-resistant coating, comprises the steps:
1) first prepare a titanium plate, preferably, wherein the purity of titanium should control at 99.7-99.99%, and the THICKNESS CONTROL of described titanium plate is at 0.2-3mm; Preferably, described titanium plate is first by addition surface treatment;
2) according to cam dimension, cam evaporative pattern is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, fixes titanium plate accordingly at cam evaporative pattern working surface, then in titanium plate surface fixed outer carbon source, described external carbon source is the graphite paper of more than three grades, purity 99%, thickness is 0.1-0.35mm, and itself and titanium plate are combined closely.
3) according to cam dimension, sand mold is made; Preferably, CO is used 2waterglass hardened sand, precoated sand, self-hardening resin sand or tide mould sand make sand mold.
4) smelt carbon steel base material for molten steel, preferably, temperature controls at 1610 DEG C-1630 DEG C;
5) adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern, titanium plate and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate; Preferably, pouring temperature controls at 1610 DEG C-1630 DEG C; More preferably, the duration of pouring, 40-50 was advisable second; Further preferably, after one minute, at hot topping, preferably, room temperature cooling.
6) the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, finally cool to room temperature with the furnace, thus form wear-resistant coating on cam work surface, and cam matrix is still plain steel.
Wherein, wear resistant carbide coating is TiC dense ceramic layers.
Preferably, by rate-determining steps 6) in temperature retention time, holding temperature obtain this TiC dense ceramic layers; Preferably, TiC dense ceramic layers is as the criterion monocrystalline phase, and described accurate monocrystalline refers to mutually, between polycrystalline phase and monocrystalline mutually between, compared to polycrystalline phase, uniform orientation is high, crystal boundary obviously reduces, and the microscopic structure that atomic arrangement is more orderly.
The present invention also provides a kind of preparation method of engine cam, and its working surface has gradient composite coating, comprises the steps:
1) first prepare a titanium plate, preferably, wherein the Pureness control of titanium is at 99.7-99.99%, and the THICKNESS CONTROL of described titanium plate is at 0.2-3mm; Preferably, described titanium plate is first by addition surface treatment;
2) according to cam dimension, cam evaporative pattern is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, titanium plate is fixed accordingly at cam evaporative pattern working surface, then in titanium plate surface fixed outer carbon source, itself and titanium plate are combined closely; Described carbon source is the graphite paper of more than three grades, purity 99%, and thickness is 0.1-0.35mm.
3) according to cam dimension, sand mold is made; Preferably, CO is used 2waterglass hardened sand, precoated sand, self-hardening resin sand or tide mould sand make sand mold.
4) smelt carbon steel base material for molten steel, preferably, temperature controls at 1610 DEG C-1630 DEG C.
5) adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern, titanium plate and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate; Preferably, pouring temperature controls at 1610 DEG C-1630 DEG C; More preferably, the duration of pouring, 40-50 was advisable second; Further preferably, after one minute, at hot topping, preferably, room temperature cooling.
6) the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, finally cool to room temperature with the furnace, thus form gradient composite coating on cam work surface, and cam matrix is still plain steel.
7) surface of gained there is gradient composite coating teeth by further heat treatment to obtain more suitably matrix.
Preferably, titanium plate thickness is 0.2-3mm; If be less than 0.2mm, then titanium plate just complete reaction in cast recombination process, can not obtain TiC dense ceramic layers, directly generation Dispersed precipitate TiC particle; Then cause diffusion length to increase more than 3mm, reaction power is not enough.
Preferably, by strict rate-determining steps 6) in holding temperature and the relation of time, obtain described accurate monocrystalline phase TiC dense ceramic layers.This ceramic layer presents comparatively obvious accurate single crystal organization, and show as crystal boundary under light microscope and reduce, affect the dislocation also corresponding minimizing of fracture toughness, the sub boundary in generation increases, and effectively improves the anti-crack ability of this ceramic layer.
Preferably, by rate-determining steps 6) in temperature retention time, holding temperature obtain this gradient composite coating and carbide coating, described carbide coating comprises the fused layer of the accurate monocrystalline phase TiC dense ceramic layers of distribution gradient successively, micron TiC ceramic layer, TiC and matrix.
More preferably, above-mentioned steps 6) in holding temperature, temperature retention time and the gross thickness of gradient composite coating that finally can obtain meet following formula,
L＝kTlogt1/2+b 0
Wherein:
The gross thickness (μm) of L---gradient composite coating,
K---be constant, value is 0-1, k ≠ 0,
T---holding temperature (K),
T---temperature retention time (s),
B 0---original depth (μm), the thickness of the composite bed formed after namely molten steel is poured into a mould and between titanium plate.
To sum up, described gradient composite coating, comprise TiC dense ceramic layers, hardness is high.Described TiC dense ceramic layers is as the criterion monocrystalline phase, and described accurate monocrystalline refers to mutually, the arrangement of atom unlike monocrystalline there is identical lattice like that, but still there is strict order, present geometry arrangement; Uniform orientation is high, crystal boundary obviously reduces, and atomic arrangement is more orderly.Accurate monocrystalline is between polycrystalline phase with monocrystalline phase, and compared to polycrystalline phase, the crystal boundary of accurate monocrystalline phase obviously reduces, and dislocation density is low, has more sub boundary, and therefore hardness has obvious lifting; And than monocrystalline phase, it requires lower to preparation method, and organize more stable.
Preferably, in step 1) in, surface-treated step is as follows:
First step pickling, selects the hydrogen peroxide of the hydrochloric acid of 300ml/L or the phosphoric acid of 60ml/L or 120ml/L, rear running water;
Second step pickling, selects the hydrogen peroxide of the hydrofluoric acid of 300ml/L or the sulfuric acid of 200ml/L or 240ml/L, rear running water;
3rd step surface finish, selects 800 orders or thinner Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.
More preferably, step 2) in external carbon source be graphite paper; Preferably, described graphite paper is more than three grades, purity 99%, and thickness is 0.1-0.35mm.
Preferably, step 6) in, be warming up to 1000-1130 DEG C of insulation, programming rate controls at 7 DEG C/min, and temperature retention time is 4-12h, preferred 6-10h.
Preferably, selected plain steel is mild steel, medium carbon steel or high-carbon steel.
Preferably, protection gas is argon gas or nitrogen, and gas flow is 4-8ml/min.
Wherein, holding temperature should be strict controlled in above-mentioned scope, and temperature is higher than 1130 DEG C, and the liquid phase in course of reaction is too much, and makes accurate monocrystalline TiC, directly generates Dispersed precipitate TiC particle, and can not obtain accurate monocrystalline TiC dense ceramic layers; But temperature is lower than 1000 DEG C, then the solubility of Ti is too low, and reaction cannot be carried out by forward.Same, temperature retention time also should keep a reasonably interval, time is more than 12h, accurate monocrystalline TiC dense ceramic layers disappears, Reaction-diffusion terms generates the fusion of Dispersed precipitate TiC particle and matrix, and lower than 4h, then reacts the TiC of acquisition very little, coating layer thickness is difficult to ensure, best should remain on 6-10h.
More preferably, the carbon steel complex with carbide coating by further heat treatment to obtain more suitably matrix; Preferably, heat-treat at about 550-800 DEG C, matrix is pearlitic structrure; Or heat-treat at 220-450 DEG C, matrix is bainite structure; Or heat-treat below 220 DEG C, matrix is martensitic structure.
Described steel matrix is preferably carbon steel, and plain steel is organized as one or more in pearlite, martensite, ferrite, bainite, austenite and sorbite.Described plain steel specifies according in standard GB/T 221-79, in this case use carbon steel the trade mark be respectively: Q275A, Q255AF, 45 steel, T12A, T8, ZG270-450 etc.
After the present invention obtains carbon steel+titanium complex by casting, introduce external carbon source, to add the mode of thermal diffusion, by controlling the relation of holding temperature, temperature retention time and coating layer thickness, carbide coating can be formed on steel surface, it is metallurgical binding between coating and plain steel, adhesion is very strong, and overcome non-metallurgical binding between existing hard particles and plain steel, adhesion is very weak, particle holds caducous problem, has increased substantially the mechanical property of coating.And the method is simple to operate, without the need to complex device, and due to the diversity of casting sand mould, be applicable to produce the wear parts with complicated shape, the parts such as such as cam.
On the other hand, the microhardness of double carbide coating of the present invention is up to 3000-3230HV 0.05, relative wear resistance is 10-22 times of plain steel.Described relative wear resistance is defined as: take matrix material as standard specimen, in identical abrasive grain, same load, after disk rotates same number of turns with same rotational speed, tested coating produces the relative wear resistance that ratio that wear extent and standard specimen produce wear extent is called coating, therefore be several times of matrix also referred to as the relative wear resistance of coating, the examination criteria of following identical parameters is identical with it.
This to be as the criterion single crystal organization due to TiC dense ceramic layers wherein, chemical stability and wearability good, there is low-friction coefficient, high rigidity, low-surface-energy and low thermal conductiv-ity.And the hardness of the micron TiC ceramic layer corresponded can only reach 2000-2800HV 0.05, its relative wear resistance is 6-10 times of matrix.
Different heat treatment modes, makes cam work surface and cam itself have different mechanical properties, meets the different performance requirement to various piece in actual production.This cam face hardness is at 3200HV 0.05left and right, disk body position has excellent wearability, be the 13-22 of ordinary steel doubly, service life significantly improves, and makes cam can free of replacement all the life.
Accompanying drawing illustrates:
Fig. 1 is engine cam preparation technology figure in the present invention;
Fig. 2 is that in the present invention, heat treatment rear engine cam and each several part organize schematic diagram;
Fig. 3 is accurate monocrystalline phase TiC ceramic layer micro-organization chart in the present invention;
Fig. 4 is TiC ceramic layer polycrystalline phase micro-organization chart in the present invention.
In figure, 1. graphite paper, 2. titanium plate, 3. block accurate monocrystalline TiC dense ceramic layers, 4. micron TiC ceramic layer, the fused layer of 5.TiC and matrix, 6. matrix, 7. cam evaporative pattern.
Detailed description of the invention
Embodiment 1:
The preparation method of engine cam, comprises the steps:
1, first prepare a titanium plate 2, wherein the purity of titanium should control 99.7%.Described titanium plate 2 should first by surface treatment in addition, and step is as follows:
First step pickling, selects the hydrochloric acid of 300ml/L, rear running water;
Second step pickling, selects the hydrofluoric acid of 300ml/L, rear running water;
3rd step surface finish, selects 800 object Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.The THICKNESS CONTROL of described titanium plate 2 is at 1mm.
2, according to engine cam size, cam evaporative pattern 7 is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, fixes titanium plate 2 accordingly at cam evaporative pattern working surface, then in the surperficial fixed outer carbon source of titanium plate 2, described carbon source is the graphite paper 1 of more than three grades, purity 99%, and thickness is 0.1mm, itself and titanium plate 2 are combined closely, as shown in Figure 1.
3, according to cam dimension, CO is used 2waterglass hardened sand makes sand mold.
4, smelt for molten steel by Q275A matrix 6, temperature controls at 1630 DEG C, and selected plain steel is mild steel.
5, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern 7, titanium plate 2 and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate 2; Preferably, pouring temperature controls at 1630 DEG C; More preferably, be advisable 40 seconds durations of pouring; Further preferably, after one minute, at hot topping, room temperature cools.
6, the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, be warming up to 1000 DEG C, programming rate controls at 7 DEG C/min, and temperature retention time is 6h, finally cools to room temperature with the furnace, obtains the double carbide coating of described cam face.Described protection gas is argon gas, and gas flow is 5ml/min.
7, the Q275A matrix 6 with carbide coating of gained, by further heat treatment to obtain more suitably matrix, heat-treats below 220 DEG C, and matrix is martensitic structure.
Described carbide coating, comprises TiC dense ceramic layers 3, and be as the criterion monocrystalline phase, and its particle diameter is 15 μm; Along coating longitudinal profile, its thickness is 110 μm, and wherein the volume fraction of TiC is 90%.
Further, comprise the micron TiC ceramic layer 4 be positioned under above-mentioned accurate monocrystalline TiC dense ceramic layers 3, along coating longitudinal profile, its thickness is 90 μm, and the volume fraction of TiC is 90%, and its particle diameter is 7 μm.
Further also comprise the fused layer 5 being positioned at TiC under above-mentioned accurate monocrystalline TiC dense ceramic layers 3 and micron TiC ceramic layer 4 and matrix, along coating longitudinal profile, its thickness is 90 μm, and wherein the volume fraction of TiC is 70%, and its particle diameter is 3 μm.
To sum up, as shown in Figure 2, described coating can be composite coating, and it comprises the fused layer 5 of accurate monocrystalline phase TiC dense ceramic layers 3, micron TiC ceramic layer 4 and TiC and matrix, and distribution gradient successively, its gross thickness is 290 μm.Described Q275A matrix 6 is organized as martensite.The microhardness of accurate monocrystalline phase TiC dense ceramic layers 3 is 3000HV 0.05, relative wear resistance is 22 times of Q275A matrix 6.
Embodiment 2:
The preparation method of engine cam, comprises the steps:
1, first prepare a titanium plate 2, wherein the purity of titanium should control 99.8%, and described titanium plate 2 should first by surface treatment in addition, and step is as follows:
First step pickling, the phosphoric acid of 60ml/L, rear running water;
Second step pickling, the sulfuric acid of 200ml/L, rear running water;
3rd step surface finish, selects 1000 object Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.The THICKNESS CONTROL of described titanium plate 2 is at 1.5mm.
2, according to cam dimension, cam evaporative pattern 7 is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, fixes titanium plate 2 accordingly at cam evaporative pattern working surface, then in the surperficial fixed outer carbon source of titanium plate 2, described carbon source is the graphite paper 1 of more than three grades, purity 99%, thickness is 0.2mm, and itself and titanium plate 2 are combined closely.
3, according to cam dimension, sand mold is made with precoated sand.
4, smelt for molten steel by Q255AF matrix 6, temperature controls at 1630 DEG C, and selected plain steel is mild steel.
5, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern 7, titanium plate 2 and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate 2; Preferably, pouring temperature controls at 1630 DEG C; More preferably, be advisable 45 seconds durations of pouring; Further preferably, after one minute, at hot topping, room temperature cools.
6, the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, be warming up to 1050 DEG C, programming rate controls at 7 DEG C/min, and temperature retention time is 6h, finally cools to room temperature with the furnace, obtains the double carbide coating of described cam face.Described protection gas is nitrogen, and gas flow is 6ml/min.
7, the Q255AF matrix 6 with carbide coating of gained, by further heat treatment to obtain more suitably matrix, heat-treats at about 700 DEG C, and matrix is pearlitic structrure.
Described carbide coating, comprises TiC dense ceramic layers 3, and be as the criterion monocrystalline phase, and its particle diameter is 30 μm; Along coating longitudinal profile, its thickness is 150 μm; Wherein the volume fraction of TiC is 90%, as shown in Figure 3.
As shown in Figure 4, further, comprise the micron TiC ceramic layer 4 be positioned under above-mentioned accurate monocrystalline TiC dense ceramic layers 3, along coating longitudinal profile, its thickness is 100 μm, and the volume fraction of TiC is 90%, and its particle diameter is 10 μm.
Further also comprise the fused layer 5 being positioned at TiC under above-mentioned accurate monocrystalline TiC dense ceramic layers 3 and micron TiC ceramic layer 4 and matrix, along coating longitudinal profile, its thickness is 100 μm, and wherein the volume fraction of TiC is 65%, and its particle diameter is 4 μm.
Now, described coating can be composite coating, is that its gross thickness is 350 μm by the fused layer 5 ecto-entad distribution gradient successively of described accurate monocrystalline TiC dense ceramic layers 3, micron TiC ceramic layer 4 and TiC and matrix.Described Q255AF matrix 6 is organized as pearlite.The microhardness of accurate monocrystalline phase TiC dense ceramic layers 3 is 3080HV 0.05, wearability is 16 times relative to Q255AF matrix 6.
Embodiment 3:
The preparation method of engine cam, comprises the steps:
1, first prepare a titanium plate 2, wherein the purity of titanium should control 99.8%.Described titanium plate 2 should first by surface treatment in addition, and step is as follows:
First step pickling, selects the hydrogen peroxide of 120ml/L, rear running water;
Second step pickling, selects the hydrogen peroxide of 240ml/L, rear running water;
3rd step surface finish, selects 1200 order Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.The THICKNESS CONTROL of described titanium plate 2 is at 2.5mm.
2, according to cam dimension, cam evaporative pattern 7 is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, fixes titanium plate 2 accordingly at cam evaporative pattern working surface, then in the surperficial fixed outer carbon source of titanium plate 2, described carbon source is the graphite paper 1 of more than three grades, purity 99%, thickness is 0.35mm, and itself and titanium plate 2 are combined closely.
3, according to cam dimension, sand mold is made with self-hardening resin sand.
4, smelt for molten steel by Q255AF matrix 6, temperature controls at 1630 DEG C, and selected plain steel is mild steel.
5, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern 7, titanium plate 2 and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate 2; Preferably, pouring temperature controls at 1630 DEG C; More preferably, be advisable 50 seconds durations of pouring; Further preferably, after one minute, at hot topping, room temperature cools.
6, the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, be warming up to 1100 DEG C, programming rate controls at 7 DEG C/min, and temperature retention time is 10h, finally cools to room temperature with the furnace, obtains the double carbide coating of described cam face.Described protection gas is nitrogen, and gas flow is 6ml/min.
7, gained Q255AF matrix 6 material, by further heat treatment to obtain more suitably matrix, heat-treats at about 700 DEG C, and matrix is pearlitic structrure.
Described carbide coating, comprise TiC dense ceramic layers 3 and to be as the criterion monocrystalline phase, its particle diameter is 40 μm; Along coating longitudinal profile, its thickness is 180 μm; Wherein the volume fraction of TiC is 90%.
Further, comprise the micron TiC ceramic layer 4 be positioned under above-mentioned accurate monocrystalline TiC dense ceramic layers 3, along coating longitudinal profile, its thickness is 130 μm, and the volume fraction of TiC is 90%, and its particle diameter is 13 μm.
Further also comprise the fused layer 5 being positioned at TiC under above-mentioned accurate monocrystalline TiC dense ceramic layers 3 and micron TiC ceramic layer 4 and matrix, along coating longitudinal profile, its thickness is 160 μm, and wherein the volume fraction of TiC is 50%, and its particle diameter is 8 μm.The now fused layer 5 ecto-entad distribution gradient successively of described accurate monocrystalline TiC dense ceramic layers 3, micron TiC ceramic layer 4 and TiC and matrix, its gross thickness is 470 μm, and described Q255AF matrix 6 is pearlite.The hardness of accurate monocrystalline phase TiC dense ceramic layers 3 is 3120HV 0.05, wearability is 22 times relative to Q255AF matrix 6.
Embodiment 4:
The preparation method of engine cam, comprises the steps:
1, first prepare a titanium plate 2, wherein the purity of titanium should control 99.8%, and described titanium plate 2 should first by surface treatment in addition, and step is as follows:
First step pickling, selects the phosphoric acid of 60ml/L, rear running water;
Second step pickling, selects the sulfuric acid of 200ml/L, rear running water;
3rd step surface finish, selects 1000 object Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.The THICKNESS CONTROL of described titanium plate 2 is at 3mm.
2, according to cam dimension, cam evaporative pattern 7 is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, fixes titanium plate 2 accordingly at cam evaporative pattern working surface, then in the surperficial fixed outer carbon source of titanium plate 2, described carbon source is the graphite paper 1 of more than three grades, purity 99%, thickness is 0.15mm, and itself and titanium plate 2 are combined closely.
3, according to cam dimension, sand mold is made; Preferably, sand mold is made with tide mould sand.
4, smelt for molten steel by 50 steel matrix 6, temperature controls at 1620 DEG C, and selected plain steel is medium carbon steel.
5, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern 7, titanium plate 2 and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate 2; Preferably, pouring temperature controls at 1620 DEG C; More preferably, be advisable 50 seconds durations of pouring; Further preferably, after one minute, at hot topping, room temperature cools.
6, the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, be warming up to 1130 DEG C, programming rate controls at 7 DEG C/min, and temperature retention time is 12h, finally cools to room temperature with the furnace, obtains the double carbide coating of described cam face.Described protection gas is nitrogen, and gas flow is 6ml/min.
7, gained 50 steel matrix 6 material, by further heat treatment to obtain more suitably matrix, heat-treats at about 350 DEG C, and matrix is bainite structure.
Described carbide coating, comprise TiC dense ceramic layers 3 and to be as the criterion monocrystalline phase, its particle diameter is 45 μm; Along coating longitudinal profile, its thickness is 200 μm; Wherein the volume fraction of TiC is 80%.
Further, comprise the micron TiC ceramic layer 4 be positioned under above-mentioned accurate monocrystalline TiC dense ceramic layers 3, along coating longitudinal profile, its thickness is 150 μm, and the volume fraction of TiC is 80%, and its particle diameter is 15 μm.
Further also comprise the fused layer 5 being positioned at TiC under above-mentioned accurate monocrystalline TiC dense ceramic layers 3 and micron TiC ceramic layer 4 and matrix, along coating longitudinal profile, its thickness is 200 μm, and wherein the volume fraction of TiC is 20%, and its particle diameter is 10 μm.Now, the fused layer 5 ecto-entad distribution gradient successively of described accurate monocrystalline TiC dense ceramic layers 3, micron TiC ceramic layer 4 and TiC and matrix, its gross thickness is 550 μm.Described 50 steel matrix 6 are bainite.The hardness of described carbide coating is 3230HV 0.05, wearability is 14 times relative to 50 steel matrix 6.
Embodiment 5:
The preparation method of engine cam, comprises the steps:
1, first prepare a titanium plate 2, wherein the purity of titanium should control 99.99%, and described titanium plate 2 should first by surface treatment in addition, and step is as follows:
First step pickling, selects the phosphoric acid of 60ml/L, rear running water;
Second step pickling, the sulfuric acid of 200ml/L, rear running water;
3rd step surface finish, selects 1200 object Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.The THICKNESS CONTROL of described titanium plate 2 is at 2.5mm.
2, according to cam dimension, cam evaporative pattern 7 is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, fixes titanium plate 2 accordingly at cam evaporative pattern working surface, then in the surperficial fixed outer carbon source of titanium plate 2, described carbon source is the graphite paper 1 of more than three grades, purity 99%, thickness is 0.25mm, and itself and titanium plate 2 are combined closely.
3, according to cam dimension, CO is used 2waterglass hardened sand makes sand mold.
4, smelt for molten steel by T12 matrix 6, temperature controls at 1610 DEG C.Selected plain steel is high-carbon steel.
5, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern 7, titanium plate 2 and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate 2; Preferably, pouring temperature controls at 1610 DEG C; More preferably, be advisable 40 seconds durations of pouring; Further preferably, after one minute, at hot topping, room temperature cools.
6, the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, be warming up to 1000 DEG C, programming rate controls at 7 DEG C/min, and temperature retention time is 12h, finally cools to room temperature with the furnace, obtains the double carbide coating of described cam face.Described protection gas is nitrogen, and gas flow is 7ml/min.
7, gained T12 steel matrix 6 material, by further heat treatment to obtain more suitably matrix, heat-treats at 400 DEG C, and matrix is bainite structure.
Described carbide coating, comprise TiC dense ceramic layers 3 and to be as the criterion monocrystalline phase, its particle diameter is 30 μm; Along coating longitudinal profile, its thickness is 120 μm; Wherein the volume fraction of TiC is 85%.
Further, comprise the micron TiC ceramic layer 4 be positioned under above-mentioned accurate monocrystalline TiC dense ceramic layers 3, along coating longitudinal profile, its thickness is 110 μm, and the volume fraction of TiC is 85%, and its particle diameter is 9 μm.
Further also comprise the fused layer 5 being positioned at TiC under above-mentioned accurate monocrystalline TiC dense ceramic layers 3 and micron TiC ceramic layer 4 and matrix, along coating longitudinal profile, its thickness is 120 μm, and wherein the volume fraction of TiC is 60%, and its particle diameter is 5 μm.Now, can by the fused layer 5 ecto-entad distribution gradient successively of described accurate monocrystalline TiC dense ceramic layers 3, micron TiC ceramic layer 4 and TiC and matrix, its gross thickness is 350 μm.Described T12 steel matrix 6 is bainite.The hardness of accurate monocrystalline TiC dense ceramic layers 3 is 3010HV 0.05, wearability is 10 times relative to T12 steel matrix 6.
Embodiment 6:
The preparation method of engine cam, comprises the steps:
1, first prepare a titanium plate 2, wherein the purity of titanium should control 99.7%.Described titanium plate 2 should first by surface treatment in addition, and step is as follows:
First step pickling, selects the hydrochloric acid of 300ml/L, rear running water;
Second step pickling, the hydrogen peroxide of 240ml/L, rear running water;
3rd step surface finish, selects 800 object Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.The THICKNESS CONTROL of described titanium plate 2 is at 2mm.
2, according to cam dimension, cam evaporative pattern 7 is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, fixes titanium plate 2 accordingly at cam evaporative pattern working surface, then in the surperficial fixed outer carbon source of titanium plate 2, described carbon source is the graphite paper 1 of more than three grades, purity 99%, thickness is 0.25mm, and itself and titanium plate 2 are combined closely.
3, according to cam dimension, sand mold is made with precoated sand.
4, smelt for molten steel by T8 steel matrix 6, temperature controls at 1610 DEG C.Selected plain steel is high-carbon steel.
5, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern 7, titanium plate 2 and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate 2; Preferably, pouring temperature controls at 1610 DEG C; More preferably, be advisable 50 seconds durations of pouring; Further preferably, after one minute, at hot topping, room temperature cools.
6, the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, be warming up to 1050 DEG C, programming rate controls at 7 DEG C/min, and temperature retention time is 12h, finally cools to room temperature with the furnace, obtains the double carbide coating of described cam face.Described protection gas is nitrogen, and gas flow is 8ml/min.
7, gained T8 steel matrix 6 material, by further heat treatment to obtain more suitably matrix, heat-treats below 220 DEG C, and matrix is martensitic structure.
Described carbide coating, comprise TiC dense ceramic layers 3 and to be as the criterion monocrystalline phase, its particle diameter is 35 μm; Along coating longitudinal profile, its thickness is 170 μm; Wherein the volume fraction of TiC is 85%.
Further, comprise the micron TiC ceramic layer 4 be positioned under above-mentioned accurate monocrystalline TiC dense ceramic layers 3, along coating longitudinal profile, its thickness is 120 μm, and the volume fraction of TiC is 85%, and its particle diameter is 12 μm.
Further also comprise the fused layer 5 being positioned at TiC under above-mentioned accurate monocrystalline TiC dense ceramic layers 3 and micron TiC ceramic layer 4 and matrix, along coating longitudinal profile, its thickness is 130 μm, and wherein the volume fraction of TiC is 55%, and its particle diameter is 6 μm.Now, be that its gross thickness is 420 μm by the fused layer 5 ecto-entad distribution gradient successively of described accurate monocrystalline TiC dense ceramic layers 3, micron TiC ceramic layer 4 and TiC and matrix.Described T8 steel matrix 6 is martensite.The hardness of accurate monocrystalline TiC dense ceramic layers 3 is 3100HV 0.05, wearability is 11 times relative to T8 steel matrix 6.
Embodiment 7:
The preparation method of engine cam, comprises the steps:
1, first prepare a titanium plate 2, wherein the purity of titanium should control 99.99%, and described titanium plate 2 should first by surface treatment in addition, and step is as follows:
First step pickling, selects the hydrogen peroxide of 120ml/L, rear running water;
Second step pickling, the hydrogen peroxide of 240ml/L, rear running water;
3rd step surface finish, selects 1200 object Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.The THICKNESS CONTROL of described titanium plate 2 is at 1mm.
2, according to cam dimension, cam evaporative pattern 7 is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, fixes titanium plate 2 accordingly at cam evaporative pattern working surface, then in the surperficial fixed outer carbon source of titanium plate 2, described carbon source is the graphite paper 1 of more than three grades, purity 99%, thickness is 0.15mm, and itself and titanium plate 2 are combined closely.
3, according to cam dimension, sand mold is made with self-hardening resin sand.
4, smelt for molten steel by ZG270-500 matrix 6, temperature controls at 1630 DEG C, and selected plain steel is mild steel.
5, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern 7, titanium plate 2 and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate 2; Preferably, pouring temperature controls at 1630 DEG C; More preferably, be advisable 45 seconds durations of pouring; Further preferably, after one minute, at hot topping, room temperature cools.
6, the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, be warming up to 1100 DEG C, programming rate controls at 7 DEG C/min, and temperature retention time is 6h, finally cools to room temperature with the furnace, obtains the double carbide coating of described cam face.Described protection gas is nitrogen, and gas flow is 8ml/min.
7, gained ZG270-500 matrix 6 material, by further heat treatment to obtain more suitably matrix, heat-treats below 220 DEG C, and matrix is martensitic structure.
Described carbide coating, comprise TiC dense ceramic layers 3 and to be as the criterion monocrystalline phase, its particle diameter is 40 μm; Along coating longitudinal profile, its thickness is 160 μm; Wherein the volume fraction of TiC is 90%.
Further, comprise the micron TiC ceramic layer 4 be positioned under above-mentioned accurate monocrystalline TiC dense ceramic layers 3, along coating longitudinal profile, its thickness is 110 μm, and the volume fraction of TiC is 90%, and its particle diameter is 11 μm.
Further also comprise the fused layer 5 being positioned at TiC under above-mentioned accurate monocrystalline TiC dense ceramic layers 3 and micron TiC ceramic layer 4 and matrix, along coating longitudinal profile, its thickness is 120 μm, and wherein the volume fraction of TiC is 60%, and its particle diameter is 7 μm.Now, the fused layer 5 ecto-entad distribution gradient successively of described accurate monocrystalline TiC dense ceramic layers 3, micron TiC ceramic layer 4 and TiC and matrix, its gross thickness is 390 μm.Described ZG270-500 steel matrix 6 is martensite.The hardness of accurate monocrystalline TiC dense ceramic layers 3 is 3110HV 0.05, wearability is 19 times relative to ZG270-500 steel matrix 6.
Embodiment 8:
The preparation method of engine cam, comprises the steps:
1, first prepare a titanium plate 2, wherein the purity of titanium should control 99.9%, and described titanium plate 2 should first by surface treatment in addition, and step is as follows:
First step pickling, selects the phosphoric acid of 60ml/L, rear running water;
Second step pickling, selects the sulfuric acid of 200ml/L, rear running water,
3rd step surface finish, selects 1000 order Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.The THICKNESS CONTROL of described titanium plate 2 is at 1mm.
2, according to cam dimension, cam evaporative pattern 7 is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, fixes titanium plate 2 accordingly at cam evaporative pattern working surface, then in the surperficial fixed outer carbon source of titanium plate 2, described carbon source is the graphite paper 1 of more than three grades, purity 99%, thickness is 0.3mm, and itself and titanium plate 2 are combined closely.
3, according to cam dimension, sand mold is made with tide mould sand.
4, smelt for molten steel by 45 steel matrix 6, temperature controls at 1620 DEG C, and selected plain steel is medium carbon steel.
5, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern 7, titanium plate 2 and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate 2; Preferably, pouring temperature controls at 1620 DEG C; More preferably, be advisable 45 seconds durations of pouring; Further preferably, after one minute, at hot topping, room temperature cools.
6, the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, be warming up to 1130 DEG C, programming rate controls at 7 DEG C/min, and temperature retention time is 6h, finally cools to room temperature with the furnace, obtains the double carbide coating of described cam face.Described protection gas is nitrogen, and gas flow is 6ml/min.
7, gained 45 steel matrix 6 material, by further heat treatment to obtain more suitably matrix, heat-treats at about 600 DEG C, and matrix is pearlitic structrure.
Described carbide coating, comprise TiC dense ceramic layers 3 and to be as the criterion monocrystalline phase, its particle diameter is 45 μm; Along coating longitudinal profile, its thickness is 170 μm; Wherein the volume fraction of TiC is 90%.
Further, comprise the micron TiC ceramic layer 4 be positioned under above-mentioned accurate monocrystalline TiC dense ceramic layers 3, along coating longitudinal profile, its thickness is 140 μm, and the volume fraction of TiC is 90%, and its particle diameter is 14 μm.
Further also comprise the fused layer 5 being positioned at TiC under above-mentioned accurate monocrystalline TiC dense ceramic layers 3 and micron TiC ceramic layer 4 and matrix, along coating longitudinal profile, its thickness is 180 μm, and wherein the volume fraction of TiC is 40%, and its particle diameter is 9 μm.The now fused layer 5 ecto-entad distribution gradient successively of described accurate monocrystalline TiC dense ceramic layers 3, micron TiC ceramic layer 4 and TiC and matrix, its gross thickness is 490 μm.Described 45 steel matrix 6 are pearlite.The hardness of accurate monocrystalline TiC dense ceramic layers 3 is 3130HV 0.05, wearability is 13 times relative to 45 steel matrix 6.
Embodiment 9:
The preparation method of engine cam, comprises the steps:
1, first prepare a titanium plate 2, wherein the purity of titanium should control 99.9%.Described titanium plate 2 should first by surface treatment in addition, and step is as follows:
First step pickling, selects the phosphoric acid of 60ml/L, rear running water;
Second step pickling, selects the sulfuric acid of 200ml/L, rear running water;
3rd step surface finish, selects 1000 order Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.The THICKNESS CONTROL of described titanium plate 2 is at 0.2mm.
2, according to cam dimension, cam evaporative pattern 7 is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, fixes titanium plate 2 accordingly at cam evaporative pattern working surface, then in the surperficial fixed outer carbon source of titanium plate 2, described carbon source is the graphite paper 1 of more than three grades, purity 99%, thickness is 0.2mm, and itself and titanium plate 2 are combined closely.
3, according to cam dimension, CO is used 2waterglass hardened sand makes sand mold.
4, smelt for molten steel by 50 steel matrix 6, temperature controls at 1620 DEG C, and selected plain steel is medium carbon steel.
5, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern 7, titanium plate 2 and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate 2; Preferably, pouring temperature controls at 1620 DEG C; More preferably, be advisable 40 seconds durations of pouring; Further preferably, after one minute, at hot topping, room temperature cools.
6, the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, be warming up to 1000 DEG C, programming rate controls at 7 DEG C/min, and temperature retention time is 4h, finally cools to room temperature with the furnace, obtains the double carbide coating of described cam face.Described protection gas is nitrogen, and gas flow is 6ml/min.
7, gained 50 steel matrix 6 material, by further heat treatment to obtain more suitably matrix, heat-treats at about 650 DEG C, and matrix is pearlitic structrure.
Described carbide coating, comprise TiC dense ceramic layers 3 and to be as the criterion monocrystalline phase, its particle diameter is 10 μm; Along coating longitudinal profile, its thickness is 70 μm; Wherein the volume fraction of TiC is 90%.
Further, comprise the micron TiC ceramic layer 4 be positioned under above-mentioned accurate monocrystalline TiC dense ceramic layers 3, along coating longitudinal profile, its thickness is 50 μm, and the volume fraction of TiC is 90%, and its particle diameter is 5 μm.
Further also comprise the fused layer 5 being positioned at TiC under above-mentioned accurate monocrystalline TiC dense ceramic layers 3 and micron TiC ceramic layer 4 and matrix, along coating longitudinal profile, its thickness is 50 μm, and wherein the volume fraction of TiC is 80%, and its particle diameter is 1 μm.Now, the fused layer 5 ecto-entad distribution gradient successively of described accurate monocrystalline TiC dense ceramic layers 3, micron TiC ceramic layer 4 and TiC and matrix, its gross thickness is 170 μm.Described 50 steel matrix 6 are pearlite.The hardness of accurate monocrystalline TiC dense ceramic layers 3 is 3000HV 0.05, wearability is 11 times relative to 50 steel matrix 6.
Embodiment 10:
The preparation method of engine cam, comprises the steps:
1, first prepare a titanium plate 2, wherein the purity of titanium should control 99.9%.Described titanium plate 2 should first by surface treatment in addition, and step is as follows:
First step pickling, selects the phosphoric acid of 60ml/L, rear running water;
Second step pickling, selects the sulfuric acid of 200ml/L, rear running water;
3rd step surface finish, selects 1200 order Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.The THICKNESS CONTROL of described titanium plate 2 is at 3mm.
2, according to cam dimension, cam evaporative pattern 7 is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, fixes titanium plate 2 accordingly at cam evaporative pattern working surface, then in the surperficial fixed outer carbon source of titanium plate 2, described carbon source is the graphite paper 1 of more than three grades, purity 99%, thickness is 0.1mm, and itself and titanium plate 2 are combined closely.
3, according to cam dimension, sand mold is made with precoated sand.
4, smelt for molten steel by Q255 matrix 6, temperature controls at 1630 DEG C, and selected plain steel is mild steel.
5, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern 7, titanium plate 2 and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate 2; Preferably, pouring temperature controls at 1630 DEG C; More preferably, be advisable 50 seconds durations of pouring; Further preferably, after one minute, at hot topping, room temperature cools.
6, the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, be warming up to 1050 DEG C, programming rate controls at 7 DEG C/min, and temperature retention time is 4h, finally cools to room temperature with the furnace, obtains the double carbide coating of described cam face.Described protection gas is nitrogen, and gas flow is 6ml/min.
7, gained Q255 steel matrix 6 material, by further heat treatment to obtain more suitably matrix, heat-treats at about 300 DEG C, and matrix is bainite structure.
Described carbide coating, comprise TiC dense ceramic layers 3 and to be as the criterion monocrystalline phase, its particle diameter is 25 μm; Along coating longitudinal profile, its thickness is 90 μm; Wherein the volume fraction of TiC is 90%.
Further, comprise the micron TiC ceramic layer 4 be positioned under above-mentioned accurate monocrystalline TiC dense ceramic layers 3, along coating longitudinal profile, its thickness is 70 μm, and the volume fraction of TiC is 90%, and its particle diameter is 8 μm.
Further also comprise the fused layer 5 being positioned at TiC under above-mentioned accurate monocrystalline TiC dense ceramic layers 3 and micron TiC ceramic layer 4 and matrix, along coating longitudinal profile, its thickness is 70 μm, and wherein the volume fraction of TiC is 70%, and its particle diameter is 2 μm.Now, the fused layer 5 ecto-entad distribution gradient successively of described accurate monocrystalline TiC dense ceramic layers 3, micron TiC ceramic layer 4 and TiC and matrix, its gross thickness is 230 μm.Described Q255 steel matrix 6 is bainite.The hardness of accurate monocrystalline TiC dense ceramic layers 3 is 3020HV 0.05, wearability is 20 times relative to Q255 steel matrix 6.
Comparative example 1, its preparation method is as follows: with laser cladding directly by the working face of titanium carbide granule cladding at cam, obtain coating, thickness is 30 μm, and volume fraction is 80%, and the hardness of gained coating is 1650HV 0.05, wearability relative to steel matrix be 2-3 doubly, and surface and matrix in conjunction with poor, cause coming off of surface accumulation layer.
In comparative example, Laser Surface Modification Technology production cost is high, and production efficiency is low, and technological parameter is wayward, and uses bonding agent will cause pore and slag inclusion in use procedure; And there is not accurate monocrystalline TiC dense ceramic layers and micron TiC ceramic layer in composite bed, composite bed thickness and TiC content less, TiC particle diameter is uneven; Simultaneously, recombination process is only that the gap externally added between hard titanium carbide granule is carried out casting and blended and carry out melting, sintering to additional particle, non-metallurgical binding between hard titanium carbide granule and steel matrix, adhesion is very weak, particle easily comes off or there is oxidation, Inclusion Problem, therefore, its mechanical property is poor.

Claims (21)

1. an engine cam, has wear-resistant coating at its working face, it is characterized in that, described wear-resistant coating is TiC dense ceramic layers.
2. engine cam as claimed in claim 1, is characterized in that, TiC dense ceramic layers is as the criterion monocrystalline phase, described accurate monocrystalline refers to mutually, between polycrystalline phase with monocrystalline phase, compared to polycrystalline phase, uniform orientation is high, crystal boundary obviously reduces, and the microscopic structure that atomic arrangement is more orderly.
3. engine cam as claimed in claim 1 or 2, it is characterized in that, along TiC dense ceramic layers along coating longitudinal profile, its thickness is 70-200 μm, is preferably 100-200 μm, is more preferably 120-200 μm; Preferably, the volume fraction of TiC is greater than 80%, is preferably greater than 90%; TiC dense ceramic layers 3 particle diameter is 8-50 μm, is preferably 10-50 μm.
4. an engine cam, has gradient composite coating at its working surface, it is characterized in that, described gradient composite coating is carbide coating, comprises the fused layer of the TiC dense ceramic layers of distribution gradient successively, micron TiC ceramic layer, TiC and matrix.
5. engine cam as claimed in claim 4, is characterized in that, TiC dense ceramic layers is as the criterion monocrystalline phase, described accurate monocrystalline refers to mutually, between polycrystalline phase with monocrystalline phase, compared to polycrystalline phase, uniform orientation is high, crystal boundary obviously reduces, and the microscopic structure that atomic arrangement is more orderly.
6. the engine cam as described in claim 4 or 5, is characterized in that, along TiC dense ceramic layers longitudinal profile, its thickness is 70-200 μm, is preferably 100-200 μm, is more preferably 120-200 μm; Wherein the volume fraction of TiC is greater than 80%, is preferably greater than 90%; Preferably, TiC particle diameter is 8-50 μm, is preferably 10-50 μm.
7. the engine cam as described in one of claim 4-6, is characterized in that, along micron TiC ceramic layer longitudinal profile, its thickness is 50-150 μm, be preferably 70-150 μm, be more preferably 80-150 μm, preferably, the volume fraction of TiC is greater than 80%, be preferably greater than 90%, preferably, the particle diameter of TiC is 5-15 μm, be preferably 6-12 μm, be more preferably 8-10 μm.
8. the engine cam as described in one of claim 4-7, it is characterized in that, along the fused layer longitudinal profile of TiC and matrix, its thickness is 50 μm-200 μm, preferred 100-200 μm, preferably, wherein the volume fraction of TiC is 20%-80%, is preferably 50%-85%, preferably, the particle diameter of TiC is 1-10 μm, is preferably 2-8 μm.
9. the engine cam as described in one of claim 4-8, is characterized in that: gradient composite coating gross thickness is 170-550 μm, preferably at 300-550 μm.
10. the engine cam as described in one of claim 4-9, is characterized in that: organize according to heat treatment be not all in pearlite, martensite, ferrite, bainite, austenite and sorbite one or more; Preferably, this gradient composite coating is applied in steel surface.
The preparation method of 11. 1 kinds of engine cams as described in one of claim 1-3, is characterized in that, engine cam working surface has wear-resistant coating, comprises the steps:
1) first prepare a titanium plate, preferably, wherein the purity of titanium should control at 99.7-99.99%, and preferably, the THICKNESS CONTROL of described titanium plate is at 0.2-3mm; Preferably, described titanium plate is first by addition surface treatment;
2) according to cam dimension, cam evaporative pattern is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, titanium plate is fixed accordingly at cam evaporative pattern working surface, then in titanium plate surface fixed outer carbon source, itself and titanium plate are combined closely;
3) according to cam dimension, sand mold is made; Preferably, CO is used 2waterglass hardened sand, precoated sand, self-hardening resin sand or tide mould sand make sand mold;
4) smelt carbon steel base material for molten steel, preferably, temperature controls at 1610 DEG C-1630 DEG C;
5) adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern, titanium plate and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate; Preferably, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the above-mentioned sand mold being placed with cam evaporative pattern, titanium plate and carbon source; Preferably, pouring temperature controls at 1610 DEG C-1630 DEG C; The duration of pouring, 40-50 was advisable second; More preferably, after one minute, at hot topping, preferably, room temperature cooling;
6) the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, finally cool to room temperature with the furnace, thus form wear-resistant coating on cam work surface, and cam matrix is still plain steel;
Wherein, wear resistant carbide coating is TiC dense ceramic layers.
The preparation method of 12. engine cams as claimed in claim 11, it is characterized in that: TiC dense ceramic layers is as the criterion monocrystalline phase, described accurate monocrystalline refers to mutually, between polycrystalline phase with monocrystalline phase, compared to polycrystalline phase, uniform orientation is high, crystal boundary obviously reduces, and the microscopic structure that atomic arrangement is more orderly; Preferably, by rate-determining steps 6) in temperature retention time, holding temperature obtain this TiC dense ceramic layers.
The preparation method of 13. 1 kinds of engine cams as described in one of claim 4-10, is characterized in that, has gradient composite coating at cam face, comprises the steps:
1) first prepare a titanium plate, preferably, wherein the purity of titanium should control at 99.7-99.99%, and the THICKNESS CONTROL of described titanium plate is at 0.2-3mm; Preferably, described titanium plate is first by addition surface treatment;
2) according to engine cam size, cam evaporative pattern is made with polystyrene foam plastics, according to the work force-bearing situation of cam, its key wear is friction strong between cam face and tappet bottom surface, titanium plate is fixed accordingly at cam evaporative pattern working surface, then in titanium plate surface fixed outer carbon source, itself and titanium plate are combined closely;
3) according to cam dimension, sand mold is made; Preferably, CO is used 2waterglass hardened sand, precoated sand, self-hardening resin sand or tide mould sand make sand mold;
4) carbon steel base material is smelted for molten steel; Preferably, temperature controls at 1610 DEG C-1630 DEG C;
5) poured into by above-mentioned molten steel in the sand mold being placed with cam evaporative pattern, titanium plate and carbon source, after molten steel cooled and solidified, take out foundry goods, sand removal process, obtaining cam matrix is carbon steel, and cam work surface is the complex of carbon steel and titanium plate; Preferably, adopt evaporative pattern process for suction casting, above-mentioned molten steel is poured in the sand mold being placed with cam evaporative pattern, titanium plate and carbon source; Preferably, pouring temperature controls at 1610 DEG C-1630 DEG C, and the duration of pouring, 40-50 was advisable second; More preferably, after one minute, at hot topping; Preferably, room temperature cooling;
6) the cam complex of having cast is put into the holding furnace inside holding with protective atmosphere, finally cool to room temperature with the furnace, thus form complex gradient coating on cam work surface, and cam matrix is still plain steel;
7) cam with gradient composite coating of gained by further heat treatment to obtain more suitably matrix.
The preparation method of 14. engine cams as claimed in claim 13, it is characterized in that, by rate-determining steps 6) in temperature retention time, holding temperature obtain this gradient composite coating and carbide coating, described carbide coating comprises the fused layer of the accurate monocrystalline phase TiC dense ceramic layers of distribution gradient successively, micron TiC ceramic layer, TiC and matrix.
The preparation method of 15. engine cams as claimed in claim 14, is characterized in that, holding temperature, temperature retention time and the gross thickness of gradient composite coating that finally can obtain meet following formula,
L＝kTlogt 1/2+b 0
Wherein:
The gross thickness (μm) of L---gradient composite coating,
K---be constant, value is 0-1, k ≠ 0,
T---holding temperature (K),
T---temperature retention time (s),
B 0---original depth (μm), the thickness of the composite bed formed after namely molten steel is poured into a mould and between titanium plate.
The preparation method of 16. engine cams as described in one of claim 13-15, is characterized in that: described step 1) in, surface-treated step is as follows:
First step pickling, selects the hydrogen peroxide of the hydrochloric acid of 300ml/L or the phosphoric acid of 60ml/L or 120ml/L, rear running water;
Second step pickling, selects the hydrogen peroxide of the hydrofluoric acid of 300ml/L or the sulfuric acid of 200ml/L or 240ml/L, rear running water;
3rd step surface finish, selects 800 orders or thinner Al 2o 3sand paper, finally uses alcohol ultrasonic cleaning.
The preparation method of 17. engine cams as described in one of claim 13-16, is characterized in that, described step 2) in external carbon source be graphite paper; Preferably, described graphite paper is more than three grades, purity 99%, and thickness is 0.1-0.35mm.
The preparation method of 18. engine cams as described in one of claim 13-17, is characterized in that: described step 6) in, be warming up to 1000-1130 DEG C of insulation, programming rate controls at 7 DEG C/min, and temperature retention time is 4-12h, preferred 6-10h.
The preparation method of 19. engine cams as described in one of claim 13-18, is characterized in that: selected plain steel is mild steel, medium carbon steel or high-carbon steel.
The preparation method of 20. engine cams as described in one of claim 13-19, it is characterized in that: described protection gas is argon gas or nitrogen, gas flow is 4-8ml/min.
The preparation method of 21. engine cams as described in one of claim 13-20, is characterized in that: described step 7) in heat treatment step be: heat-treat at about 550-800 DEG C, matrix is pearlitic structrure; Or heat-treat at 220-450 DEG C, matrix is bainite structure; Or heat-treat below 220 DEG C, matrix is martensitic structure.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104879179A (en) * 2015-06-01 2015-09-02 扬州意得机械有限公司 Engine cam and machining method thereof
CN115700264A (en) * 2022-12-01 2023-02-07 丹阳市磊晶机械制造有限公司 High-strength wear-resistant camshaft

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59205473A (en) * 1983-05-02 1984-11-21 Nissan Motor Co Ltd Preparation of cam shaft
CN1297797A (en) * 2000-09-14 2001-06-06 四川大学 Cam shaft of iron-base surface composite material and its manufacture
CN1570194A (en) * 2003-07-25 2005-01-26 建湖刚玉金属复合材料有限公司 Infiltrated titanium carbide(TiC)- steel gradated material making technology
CN103953407A (en) * 2014-04-25 2014-07-30 苏州工业园区职业技术学院 Engine camshaft and preparation method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59205473A (en) * 1983-05-02 1984-11-21 Nissan Motor Co Ltd Preparation of cam shaft
CN1297797A (en) * 2000-09-14 2001-06-06 四川大学 Cam shaft of iron-base surface composite material and its manufacture
CN1570194A (en) * 2003-07-25 2005-01-26 建湖刚玉金属复合材料有限公司 Infiltrated titanium carbide(TiC)- steel gradated material making technology
CN103953407A (en) * 2014-04-25 2014-07-30 苏州工业园区职业技术学院 Engine camshaft and preparation method thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
材产: "特殊准单晶物质", 《军民两用技术与产品》 *
韩杰才等: "金属/陶瓷梯度涂层工艺现状", 《材料工程》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104879179A (en) * 2015-06-01 2015-09-02 扬州意得机械有限公司 Engine cam and machining method thereof
CN115700264A (en) * 2022-12-01 2023-02-07 丹阳市磊晶机械制造有限公司 High-strength wear-resistant camshaft

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